Move zygote startup logic to the frameworks.
The Zygote class is now in com.android.internal.os. It is
responsible for the vast majority of work before and after
the call to fork(). It calls back into the Runtime via
the new dalvik.system.ZygoteHooks class to allow the Runtime
to perform pre fork cleanup and post fork initialization.
The native code in Zygote.cpp is a direct and straightforward
port of the existing code in art. Most differences are
superficial, for example :
- We use C style logging (ALOGE) instead of stream based
logging.
- We call env->FatalError() instead of using LOG(FATAL)
Change-Id: Ia101fb2af12d23894fe57e4134d2bc6d142e5059
diff --git a/core/java/com/android/internal/os/Zygote.java b/core/java/com/android/internal/os/Zygote.java
new file mode 100644
index 0000000..c5fa0a1
--- /dev/null
+++ b/core/java/com/android/internal/os/Zygote.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.os;
+
+
+import dalvik.system.ZygoteHooks;
+import libcore.io.ErrnoException;
+import libcore.io.Libcore;
+
+/** @hide */
+public final class Zygote {
+ /*
+ * Bit values for "debugFlags" argument. The definitions are duplicated
+ * in the native code.
+ */
+
+ /** enable debugging over JDWP */
+ public static final int DEBUG_ENABLE_DEBUGGER = 1;
+ /** enable JNI checks */
+ public static final int DEBUG_ENABLE_CHECKJNI = 1 << 1;
+ /** enable Java programming language "assert" statements */
+ public static final int DEBUG_ENABLE_ASSERT = 1 << 2;
+ /** disable the JIT compiler */
+ public static final int DEBUG_ENABLE_SAFEMODE = 1 << 3;
+ /** Enable logging of third-party JNI activity. */
+ public static final int DEBUG_ENABLE_JNI_LOGGING = 1 << 4;
+
+ /** No external storage should be mounted. */
+ public static final int MOUNT_EXTERNAL_NONE = 0;
+ /** Single-user external storage should be mounted. */
+ public static final int MOUNT_EXTERNAL_SINGLEUSER = 1;
+ /** Multi-user external storage should be mounted. */
+ public static final int MOUNT_EXTERNAL_MULTIUSER = 2;
+ /** All multi-user external storage should be mounted. */
+ public static final int MOUNT_EXTERNAL_MULTIUSER_ALL = 3;
+
+ private static final ZygoteHooks VM_HOOKS = new ZygoteHooks();
+
+ private Zygote() {}
+
+ /**
+ * Forks a new VM instance. The current VM must have been started
+ * with the -Xzygote flag. <b>NOTE: new instance keeps all
+ * root capabilities. The new process is expected to call capset()</b>.
+ *
+ * @param uid the UNIX uid that the new process should setuid() to after
+ * fork()ing and and before spawning any threads.
+ * @param gid the UNIX gid that the new process should setgid() to after
+ * fork()ing and and before spawning any threads.
+ * @param gids null-ok; a list of UNIX gids that the new process should
+ * setgroups() to after fork and before spawning any threads.
+ * @param debugFlags bit flags that enable debugging features.
+ * @param rlimits null-ok an array of rlimit tuples, with the second
+ * dimension having a length of 3 and representing
+ * (resource, rlim_cur, rlim_max). These are set via the posix
+ * setrlimit(2) call.
+ * @param seInfo null-ok a string specifying SELinux information for
+ * the new process.
+ * @param niceName null-ok a string specifying the process name.
+ * @param fdsToClose an array of ints, holding one or more POSIX
+ * file descriptor numbers that are to be closed by the child
+ * (and replaced by /dev/null) after forking. An integer value
+ * of -1 in any entry in the array means "ignore this one".
+ *
+ * @return 0 if this is the child, pid of the child
+ * if this is the parent, or -1 on error.
+ */
+ public static int forkAndSpecialize(int uid, int gid, int[] gids, int debugFlags,
+ int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose) {
+ VM_HOOKS.preFork();
+ int pid = nativeForkAndSpecialize(
+ uid, gid, gids, debugFlags, rlimits, mountExternal, seInfo, niceName, fdsToClose);
+ VM_HOOKS.postForkCommon();
+ return pid;
+ }
+
+ native private static int nativeForkAndSpecialize(int uid, int gid, int[] gids,int debugFlags,
+ int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose);
+
+ /**
+ * Special method to start the system server process. In addition to the
+ * common actions performed in forkAndSpecialize, the pid of the child
+ * process is recorded such that the death of the child process will cause
+ * zygote to exit.
+ *
+ * @param uid the UNIX uid that the new process should setuid() to after
+ * fork()ing and and before spawning any threads.
+ * @param gid the UNIX gid that the new process should setgid() to after
+ * fork()ing and and before spawning any threads.
+ * @param gids null-ok; a list of UNIX gids that the new process should
+ * setgroups() to after fork and before spawning any threads.
+ * @param debugFlags bit flags that enable debugging features.
+ * @param rlimits null-ok an array of rlimit tuples, with the second
+ * dimension having a length of 3 and representing
+ * (resource, rlim_cur, rlim_max). These are set via the posix
+ * setrlimit(2) call.
+ * @param permittedCapabilities argument for setcap()
+ * @param effectiveCapabilities argument for setcap()
+ *
+ * @return 0 if this is the child, pid of the child
+ * if this is the parent, or -1 on error.
+ */
+ public static int forkSystemServer(int uid, int gid, int[] gids, int debugFlags,
+ int[][] rlimits, long permittedCapabilities, long effectiveCapabilities) {
+ VM_HOOKS.preFork();
+ int pid = nativeForkSystemServer(
+ uid, gid, gids, debugFlags, rlimits, permittedCapabilities, effectiveCapabilities);
+ VM_HOOKS.postForkCommon();
+ return pid;
+ }
+
+ native private static int nativeForkSystemServer(int uid, int gid, int[] gids, int debugFlags,
+ int[][] rlimits, long permittedCapabilities, long effectiveCapabilities);
+
+ private static void callPostForkChildHooks(int debugFlags) {
+ VM_HOOKS.postForkChild(debugFlags);
+ }
+
+
+ /**
+ * Executes "/system/bin/sh -c <command>" using the exec() system call.
+ * This method throws a runtime exception if exec() failed, otherwise, this
+ * method never returns.
+ *
+ * @param command The shell command to execute.
+ */
+ public static void execShell(String command) {
+ String[] args = { "/system/bin/sh", "-c", command };
+ try {
+ Libcore.os.execv(args[0], args);
+ } catch (ErrnoException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ /**
+ * Appends quotes shell arguments to the specified string builder.
+ * The arguments are quoted using single-quotes, escaped if necessary,
+ * prefixed with a space, and appended to the command.
+ *
+ * @param command A string builder for the shell command being constructed.
+ * @param args An array of argument strings to be quoted and appended to the command.
+ * @see #execShell(String)
+ */
+ public static void appendQuotedShellArgs(StringBuilder command, String[] args) {
+ for (String arg : args) {
+ command.append(" '").append(arg.replace("'", "'\\''")).append("'");
+ }
+ }
+}